The correct option is A \N
We know thattan (π4)=1tan (3π4)=−1as 3π4 lies in the 2nd quadrantalso tan (5π4)=1as 5π4 lies in the 3rd quadrantand, tan (7π4)=−1as 7π4 lies in the 4th quadrant.Thus,tan (π4)+tan (3π4)+tan (5π4)+tan (7π4)=1−1+1−1=0
Thus, 0 is the correct answer.